The invention relates to an electric lamp comprising:
a translucent lamp vessel in which an electric light source is arranged; PA1 a lamp cap with an axis whose wall mainly consists of synthetic material and which has electrical contacts on its outer side; PA1 current-supply conductors extending from the light source to electrical contacts at the lamp cap, PA1 the lamp vessel being partly sunk into the lamp cap and being fixed on the inner side thereof by means of cement, PA1 and a metal ring in contact with the cement being present in the lamp cap.
Such a lamp is known from German Patent Specification No. 452 751 (Patent Treuhand Gesellschaft No. 18-111927).
With the use of a lamp cap of electrically insulating material, it may be difficult to cure the cement with which the lamp vessel has to be fixed in the lamp cap because the lamp cap poorly conducts the heat required for this curing process.
According to the aforementioned German Patent Specification, a metal ring, which is in contact with the cement, is present in the lamp cap so that the cement can be cured by inductively heating the ring. The heat then need not be transported through the wall of the lamp cap to the interior. The metal ring is sunk into the wall of the lamp cap on the inner side thereof. In another known lamp, the ring is located loosely in the lamp cap before the cement is cured.
It has been found that the use of the metal ring in a lamp cap of synthetic material, in order to heat and to cure the cement by inductively heating the ring, involves the risk that the lamp cap is heated excessively by the metal ring and is consequently deformed.